The purpose of this study is to investigate the effects of flumazenil on cortical excitability in healthy human volunteers. Flumazenil acts as a potent benzodiazepine (BZP)-specific antagonist by competing at the central synaptic gamma-aminobutyric acid (GABA) receptor site. However, the relationship between GABA and flumazenil without BZPs is not well known. We plan to determine if intravenous (IV) administration in therapeutic dosage alters cortical excitability as measured by transcranial magnetic stimulation (TMS). The long-term plan is to identify a pharmacological method to reduce cortical inhibition that might be useful in stroke rehabilitation.